The current proposal seeks to determine putative differences in the cerebral lateralization of speech and language functions in left-and right-handed males and females. This research will be carried out on normal and unilaterally brain-injured (stroke) subjects. In the former studies, various measures of cerebral and motor laterality will be administered to infer probable mode of cerebral speech specialization. In the latter studies, incidence and type of aphasia will be assessed in consecutive cases of unilateral vascular disease to infer the probable mode of speech organization. This inference will be based on a quantitative method recently developed by the PI. These continued laboratory and clinical studies are designed to provide new answers to the controversial problem of gender and hand differences in cerebral dominance.